CD 004
Weeding Guidelines
Revised January 2007
GENERAL WEEDING GUIDELINES
Continuous weeding is necessary to maintain collections so that they offer a
balance between standard classics and the currently popular while eliminating
incorrect information and worn books. Collections should also reflect usage
patterns and trends, as topics and formats may need to be weeded based on
waning customer interest.
It is important to note that weeding is always based on professional judgment.
Just as in selection, the content of the current collection, resource sharing,
materials available from publishers and producers and community needs must
all be considered in decision making. In weeding certain areas, such as religion
or social sciences, a balance of viewpoints must be maintained. Having material
available on a wide range of reading levels is also a goal for most locations.
Main Library may wish to retain selected materials for historical perspective.
Neighborhood libraries should consider weeding items that have been
superseded by updated information.
For some subjects, however, such as medicine, no information is better than
outdated or inaccurate information. In others, such as technology and science,
finance and the law, materials may date rapidly. In most cases, out-of-date
titles should not be retained even if nothing else is available in the collection.
When considering whether to weed items that would leave a collection lacking
in a particular area, it may be helpful to consult the online catalog to determine
whether more up-to-date materials are available either in print from other
locations or in electronic format. Of course, the decision may also be made to
request or select new titles on the topic.
The purpose of weeding is to:
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Utilize available space in the best and most economical way
Maintain up-to-date collections and the library’s reputation
for reliability
Increase speed of access and improve accuracy of retrieval
Remove books least likely to be used in the future
Increase circulation
Locate books that need to be repaired, rebound or replaced
Save expense of housing materials unnecessarily
Review collection for content and identify areas where
additional titles are needed
Become aware of changes in the way the community uses the
collection.
Criteria for weeding:
CONDITION - Materials in poor condition are prime candidates for replacement.
Weed items which have the following defects:
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Loose, frayed or broken bindings
Yellow, brittle pages
Soiled covers and pages
Missing pages and illustrations
Heavily marked pages
Mutilation or damage
CONTENT – Books may be in excellent physical condition but contain
inaccurate information or be presented in such as way as to warrant weeding.
Weed based on the following criteria:
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Superseded editions (i.e. a newer edition is available)
Outdated language, photographs or illustrations
Ephemeral; waning interest
Dated or inaccurate information
Duplicate copies, when interest has diminished
Out-of-date exam and test books in all subjects
Trivial subject matter
USE - Inventory reports on selected areas that show the frequency of circulation
and/or the most recent circulation may be generated from data collected by the
ILS. Generally, items that have not circulated for three years and are not
needed for reference should be evaluated for discard. In smaller, more crowded
collections or with more popular formats, such as DVD, it may be more useful
to consider items that have not circulated in the last year as possible
candidates for withdrawal.
When to weed:
Ideally, weeding is an ongoing activity. This is easiest to achieve when weeding
for condition. Clerical and page staff can be trained to set aside materials in
poor condition for consideration by the librarian.
When weeding for content, developing a regular schedule is helpful. One
possibility is to have an actual weeding calendar. An annual or multi-year cycle
may be created that ensures that all areas of the collection are weeded on a
regular basis.
Another option is to identify certain topics or formats that can be weeded
following periods of peak popularity. For example, books on Christmas,
Hanukkah and Kwanzaa could be weeded each January on the assumption that
any titles not popular during the current season are unlikely to develop
additional appeal by sitting on a shelf for a year.
Another possibility is to link weeding to other activities. For example, weeding
is a natural accompaniment to selection. When selecting materials for a
specific area, whether from a selection list provided by the Collection Services
staff or independently, review the materials on the subject that are currently
owned and identify any that may be replaced by the new titles.
How to weed:
Examine the library's Collection Development and Management Policy.
Consider the library’s mission and the demographics of your community.
Examine usage statistics, if possible. Consult and use the weeding guidelines.
Involve your staff and work as a team. Arrange for discreet discarding of
materials.
How much to weed:
In locations where collections are already at optimum levels, it’s necessary to
weed as many items as are received throughout the year. This keeps the
collection size constant and provides for ease of use and sufficient display
opportunities. When space is not an issue, weed for content and condition.
Assistance with weeding:
Collection Services staff members are happy to consult on weeding projects or
provide on-site assistance with weeding.
WEEDING BY CATEGORY
General Reference and Encyclopedias
Stagger replacement sets; one set should be replaced each year. When the new
edition is received, previous edition may be circulated. The oldest reference
encyclopedia should be no more than three to five years old. Circulating
encyclopedias should be no more than five to seven years old. Do not weed
specialized encyclopedias that are updated irregularly such as the Encyclopedia
Judaica and New Catholic Encyclopedia. Retain until the new edition is
available. Some reference volumes, such as quotation books, should be kept
because later editions augment rather than supersede.
Continuations (such as almanacs, annuals, directories, etc.)
Weed superseded edition when new edition is received. The superseded edition
may be circulated. Do not keep more than one or two superseded editions.
Keep only one previous edition of the Physicians' Desk Reference.
Biographies
Weed as demand lessens. Celebrity biographies should be weeded as interest
wanes. Consider the reputation and popularity of the biographer.
Job and Career Information
Any career books that contain salary information should be weeded after three
years. More specific guidelines follow:
College Guides - weed after 3 years.
Job Hunting - general texts may be kept up to five years.
Resume Books – currency is critical, replace with new editions as they are
published.
Test Books - replace with new edition as available.
GED - discard titles after 5 years.
SAT and Praxis – delete books that use the old format (prior to 2005).
Travel
Weed after three years unless focus is more on history and culture than
accommodations and attractions. For titles not updated annually, such as the
Lonely Planet guides, retain existing copy until new edition is received.
WEEDING NON-FICTION BY CLASSIFICATION
A – General Collection
000
Guinness Book of World Records and similar titles - keep current edition
and one previous edition.
Atlases - weed superseded edition and those that do not reflect current
conditions, even if new edition is not available. A limited number of
atlases may be needed for genealogy and historical purposes and,
therefore, should not be weeded; these are generally held by Main
Library.
B - Philosophy, Psychology, Religion, Etiquette, etc.
100
Philosophy - weed on condition and use; should maintain a core
collection. Retain specific philosophical viewpoints, e.g. existentialism.
Retain landmark philosophies that shaped history.
Parapsychology/Occult—weed on condition and use.
150
Psychology - weed on condition and use; "pop" psychology titles older
than three to five years should be weeded unless author is well known.
Keep psychology textbooks for five years only. Review for detailed
theories, pictures and concepts.
200
Religion - weed on condition, keeping current basic material on all
religions and sects for a representative collection, especially reflecting
your community's beliefs. Keep titles of popular nature no more than
five years unless author is well known.
Mythology - weed only on condition for Greek and Roman mythology;
others should be judged on use.
390
Etiquette - weed titles more than five years old. Weed outdated concepts
and replace with current material.
C - Archaeology, Genealogy, Coins and Flags
737
Coins – discard price guides after one to two years unless of historical
value.
913
Archaeology – weed on condition and use.
929
Genealogy – weed on condition and use.
Flags – weed out-of date books.
D – History, Current Affairs
900
General History – weed on condition, use, accuracy of fact and fairness of
interpretation.
Current Affairs – weed after three to five years; Main Library may retain
selected materials as needed for historical perspective.
E – History of North America, including the United States
970
History – weed on condition and use.
Current Conditions – weed after three to five years; Main Library may
retain selected materials as needed for historical perspective.
F – State and Local History, Central and South America
980
History – weed on condition and use.
Current Conditions – weed after three to five years; Main Library may
retain selected materials as needed for historical perspective
Local History – retain all local history as condition and use warrant.
Materials from branch collections must be offered to Pennsylvania
Department before withdrawal.
G - Geography, Anthropology, and Recreation
570
Anthropology – watch for new developments, discoveries and theories.
790
Sports/Games – weed for out-of-date rules, generally three years and
older.
910
Geography – watch for dated material, changes in countries’ names.
Weed road atlases and maps after three years.
H – Social Sciences
300
Economics, Business and Personal Finance—all age rapidly. Watch for
titles that do not reflect recent trends. Except for histories and some
classical theoretical texts, almost all material is out of date after three to
five years.
Investment – must be kept current. Weed as interest wanes in a
particular type of investment. “Classic” works (those of historical or
theoretical value) may be retained according to usage.
Real Estate – watch for changes in real estate law, financing, taxes.
Sociology - weed on condition and use. Weed "pop" sociology titles more
than three to five years old unless author is well known. Weed true
crime titles according to demand, use, condition, and timeliness,
generally after three to five years, unless author is well known.
Weed titles that do not reflect current understanding and treatment of
social problems. The collection should present a diversity of life styles
and maintain a balance on controversial issues.
Stamps - keep two years. Also keep catalogs and price guides for two
years, depending on use and shelf space. General information on stamp
collecting may be retained as use warrants.
J - Political Science
320
Weed on condition, use and timeliness. Watch for titles that contain outof-date information on government office holders, etc. Texts on
citizenship must be current. Keep popular titles up to three years;
historical titles up to five years.
K - Law
340
Law titles which pertain to property ownership, real estate, estate
planning, probate, wills, business, real estate investment trusts, income
tax, pension, social security and taxes should be weeded after three to
five years and checked regularly for accuracy and timeliness. Books that
are superseded by a new edition should be discarded.
Weed out-of-date titles on the Constitution and Supreme Court. Only
history of law should be over five years old.
Income tax guides – Keep current year plus one. Larger libraries may
elect to keep older copies for seven years to meet IRS audit requirements.
L – Education
370
Weed on condition, use, and for out-of-date theory and methodology.
Keep historical information if used.
M-N - Music and the Arts
700
Music - weed on condition and use. Keep histories and basic material,
especially songbooks.
Fine Arts - weed on condition and use. Keep standard art history titles,
checking for condition and quality of illustrations.
Architecture - keep historical material and weed on condition and use.
Antiques - keep basic books, without prices, based on use and condition.
Weed price guides after three years.
Interior Design - weed according to taste changes.
Drawing and Painting - keep five to ten years as use and condition
warrant.
Sculpture - keep history according to condition. Keep techniques five to
ten years.
P - Literature and Language
400-800
Literature - weed on condition and use. Dictionaries should reflect
current usage; books on grammar may be kept up to ten years. Maintain
representative collections of anthologies. Keep basic materials, especially
criticism of classic writers. Retain standard reference titles that are outof-print. Consideration must be given to local/area student reading lists,
local authors, and special collections.
Poetry - keep basic authors; check for use of minor poets.
Plays - keep, based on interest and condition.
Humor - keep fresh and new; much is dated after five years, but retain
standards.
Languages - discard outdated and unattractive textbooks and grammars
and weed according to use. Stock dictionaries for languages being
studied and/or spoken in your community.
Folklore/Fairy Tales - weed as use and condition justify. Fairy and folk
tales should reflect a range of countries and cultures. Regional folklore
should be represented.
Q - Science
500
Science needs to be continually evaluated and kept up-to-date. Watch
for new discoveries and theories. Computer science, electronics, and
space science age rapidly and must be weeded in an on-going fashion.
Mathematics, chemistry and botany do not change as quickly, but
should be reviewed regularly. The history of science should be weeded
sparingly. Retain most science biographies.
Computers - evaluate theory and application. Discard personal
computer theory after five to ten years. Keep discussion of specific
models and peripherals for no more than three to five years; Main Library
should keep materials to meet demand. Evaluate programming on use.
Keep buying guides for two years only. Keep computer languages until
surpassed by a new version.
Mathematics – mathematics does change, especially in teaching style and
course emphasis. Histories should be up to date. Discard fad materials
and old technology such as “new math,” slide rules, finger math, etc.
Keep logic and basic math for ten years. Certain titles may be
considered classics and should be retained indefinitely.
Astronomy – Watch for changes in planet, solar system and universe
information. Currency is important. Stargazing changes less rapidly,
but equipment is updated.
Chemistry and Physics – chemistry and physics are areas that change
rapidly. Check for the correct number of elements in the Periodic Table.
Geology – check for updated theories and terms. For example, plate
tectonics rather than continental drift.
Paleontology and Dinosaurs – watch for new developments and new
theories (e.g. new information about dinosaurs).
Biology and Genetics – In general weed after five to ten years, however
watch for new discoveries and theories, which are frequent in human
biology and especially genetics. Weed genetics after three to five years.
Microbiology - weed after five years
Anatomy and Physiology - anatomy may be retained almost indefinitely;
physiology should be weeded after five to ten years
Classic works in all fields of science should be retained indefinitely, such
as Darwin, Einstein, Newton and Audubon.
Science Experiments - weed out-of-date science fair materials as they
may contain potentially harmful compounds or dangerous chemical
experiments.
R – Medicine
610
Books in this field must be evaluated regularly and all obsolete materials
must be discarded, especially in areas such as pharmacology and
therapeutics. Retain classics and related books written by authorities on
subjects still referred to by today’s physicians.
The American Medical Association recommends that all books on
medicine and health, including diet and nutrition, be no more than
three to five years old.
Standard works from such organizations as the AMA, ADA, Mayo Clinic
and related health care settings should be retained until new editions are
available.
Watch for changes in the theory and treatment of specific conditions and
diseases that necessitate weeding more frequently. Do not put older
medicine and health titles in book sales.
S – Plant and Animal Science
630
Gardening – weed on condition, use and timeliness. Watch for changes in
hybrids and gardening techniques, use of pesticides, and the handling of
lawn and garden waste.
Pets – Veterinary medicine parallels human medicine and must be kept
current. Animal training should be kept as use and popularity indicate.
Be aware that breed standards change.
T – Technology, Handicrafts, and Home Economics
600-700
Technology – watch for changes in equipment, methods and fads.
Otherwise, weed on condition and use. History of technology should be
retained indefinitely.
Inventions – the history of inventions and inventors may be kept
indefinitely unless condition dictates withdrawal.
Cookbooks – weed based on condition, demand, and cookery
style. Retain those with historical value.
Handicrafts – weed based on demand, retain basic technique books if
well illustrated.
Sewing and Grooming – sewing, makeup and hairstyling books all date
quickly; weed outdated fashions and styles.
Photography – check for outdated techniques and equipment.
Collections and histories may be kept as long as use, condition and
space allows.
Appliance and Auto Repair - keep as long as interest and use dictate.
U-V – Military Science, Naval Science
620
Weed on condition and use. Watch for changes in military hardware and
technology.
Armed Forces test guides must be kept current.
Z – Bibliography and Library Science
000
Bibliographies – must have supporting material easily accessible.
Library Science – discard all practical guides that do not conform to
current practice and technologies. Retain histories according to usage.
WEEDING GIFT ITEMS FROM THE COLLECTION
Weeding guidelines for gift books are no different than those for purchased
materials. The presence of a bookplate does not make an item exempt from
withdrawal. The collection development criteria used when selecting new titles
should be employed when assessing gift books. Never add a gift item that
would not have been purchased. The cost for processing gifts, possible shelf
life, and interest are major considerations.
WEEDING FICTION
Fiction can be a very difficult area to weed because in many cases it does not
obviously become outdated. However, just as styles in clothing change, there
are definite trends in literature, particularly light leisure reading and genre
fiction. This is especially true in collections for children and teens whose
readers have and express strong preferences for certain types of materials.
For example, among children and teens a passion for horror characterized the
late 1980s and early 1990s, while readers today clamor for fantasy titles. Chick
lit has held similar sway over adult readers in recent years while urban fiction
continues to gain momentum. So, while some classics may remain of interest
and certain authors should always be represented in collections, many
customers do prefer contemporary titles for much of their leisure reading.
For guidance in weeding fiction, keep in mind the library’s collection
development policy and mission as well as individual community’s
demographics and interests. When weeding a genre or section of the collection
that is unfamiliar, consult a source such as Genreflecting. Remember that
sometimes as an author becomes more popular, his or her older works will be
more in demand (and may be more difficult to find).
Generally if a fiction book has not circulated in the last three years, it should be
considered a candidate for weeding. For some libraries that time period may be
shorter, depending upon the size of the branch and the collection.
For current fiction with general appeal and classic titles, replacing a worn title
with a new more attractive copy may boost circulation. Be careful, however, not
to weed fiction based solely on condition. Considering condition can be a quick
way to evaluate the collection and identify unattractive items that should be
considered for withdrawal, but remember that titles become worn because
people are reading them. If a book has been owned for several years and is still
in pristine condition it may also be a prime candidate for weeding.
Books in series require special consideration. Some series are sequential and
are best when read in order (Harry Potter, for example or Janet Evanovich’s
Stephanie Plum novels) while others may feature repeat characters but need
not be read in sequence. For sequential series it is helpful to retain the
complete run while interest is strong if the size of your collection permits.
Remember that the release of a new title in a sequential series may create
interest in older titles.
WEEDING AUDIO-VISUAL MATERIALS
Circulation statistics can be particularly useful when weeding a/v materials.
Generally, items in these collections are used frequently; review for condition
after 75-100 circulations. If an item isn’t circulating well, it is also a candidate
for removal.
Condition is a key consideration. Watch for damaged items or those with
incomplete packaging, e.g. missing liner notes.
When weeding for content, a/v materials should be discarded using the same
criteria used for print.
Discard obsolete formats that have been superseded by new technology.
Spoken word – weed heavily when formats become outdated.
Video – weed heavily when formats become outdated.
Music – titles should be withdrawn as artists decline in popularity and demand
wanes, particularly in branches. Maintain coverage of current musical trends,
as well as standard and perennially requested titles.
Electronic – weed for age and content
WEEDING TEENS AND CHILDREN’S MATERIALS
Condition is often the most useful criteria to consider in weeding these
collections. For materials in good condition, however, the same guidelines
should be used in weeding material for all ages. Younger library users deserve
materials that have been held to the same standards of accuracy and currency
as the rest of the collection. Indeed, children and teens may be less likely than
adults to recognize superseded or inaccurate information, making it even more
important to keep these collections up-to-date.
In particular, nonfiction should be current, accurate and on an appropriate
reading level for the intended audience. Visual presentation is important and
tables or graphs should be easy to understand while illustrations should be
clear and engaging. Information presented in an outdated, text-only format
should be closely evaluated.
Fiction titles should also be kept up-to-date. While some classic stories have
stood the test of time, many realistic fiction titles for children should be kept
only as long as they accurately reflect current conditions. Cover illustrations
that clearly belong to a previous decade, out-of-date slang and other obvious
indicators of a book’s age should be taken into consideration when weeding
children’s fiction. Remember that children’s frame of reference for memories
and experiences are much shorter than our own.
These recommendations apply even more strongly for teen titles. Teen readers
are very aware of current trends and therefore it is important to make sure that
the covers of books are up-to-date and aesthetically appealing. Maintaining a
fresh selection of fiction for teens may occasionally mean weeding titles that are
only a few years old.